I have noticed on numerous shots I have taken at FLL and MIA over the past few weeks that AA's 752's seam to have a black (rubber) mark near the first A in American. I have probably seen close to 15-20 a/c with that mark in the same area. Anyone have a clue as to what it is. Thanks, Ed

I think that you are referring to dirt coming from the air bridges. Look at the photo below. This AA 757 has dirt over the first A letter and also behind the cockpit windows. The dirt comes from the bridge.